Julian Assange, the beleaguered inventor of WikiLeaks, stood on the Belmarsh courtroom steps and delivered what has become a familiar harangue against those trying to extradite him to Sweden, where he is accused of sexual misconduct. The climax of almost a quarter of an hour of oration came when he complained of "this ridiculous time I have to spend on this nonsense!". Such was his dismissive reaction to a reasoned 28-page ruling by the district judge, Howard Riddle, who no doubt burned some midnight oil composing findings he knows will be scrutinised carefully by an appeal court.

It might have been more diplomatic of Assange to have kept quieter, following a devastating finding in the judgment that one of Assange's fleet of lawyers, the Swedish advocate Björn Hurtig, made "a deliberate attempt to mislead the court". It was a striking reminder of the dangers over-enthusiastic solicitors face when they cross the line and engage in media grandstanding.

The issue could not have been more crucial: the Assange team had attempted to give the impression that the Swedish prosecutor Marianne Ny had behaved in an "astonishing" and improper manner, by making no attempt to interview Assange while he was in Sweden, and then unscrupulously chasing after him in England to have him arrested. This false allegation was bolstered with unsubstantiated claims that Ny, the senior sex crimes specialist prosecutor, was a "malicious radical feminist".

Apparently undaunted by the wholesale rejection of his case, Assange shifted tack to mount a lengthy attack against the entire European arrest warrant system, which, as he said, was devised after the 2001 terrorist atrocities of 9/11 to make it easier to bring Islamist suspects to justice in European courts.

He may well have a point about the subsequent overuse and abuse of the warrants. State power frequently needs watching and curbing. But he is scarcely well placed to be a disinterested advocate of British legal reform, while he is himself frantically trying to avoid facing the music in Sweden. Nor do his pious remarks about "our system of justice" make much sense when they come from a peripatetic Australian citizen who has made a virtue out of a nomadic, virtually stateless, existence that circumvented traditional systems of justice.

Assange has now been mired in what he calls this "nonsense" for a considerable time – since six months ago, when two Swedish women went to the Stockholm police complaining about Assange's sexual behaviour.

This might seem like "nonsense" in Assange's eyes. He has previously said the women got into a "tizzy" and were "bamboozled" by police. He has sought in this way to wage a high-profile information war about what ought to have remained his private life, through hearing after hearing, interview after interview, and has repeatedly tried to blur the boundary between the sex allegations and the attacks on him by US politicians because he masterminded the WikiLeaks free speech exposures . He was at it again on Thursday, talking about "the pressure the US brings to bear on the UK, on Sweden and on the media".

Meanwhile, the night before the Belmarsh verdict, the editors of the five international publications involved in the leaks gathered in Madrid. The Guardian, the New York Times, El País, Der Spiegel and Le Monde debated before an audience, but with much less fanfare, the real issues thrown up by the pioneering work of WikiLeaks. Has the exposure of the US diplomatic cables made it harder for governments to lie in the age of the internet? How far did WikiLeaks contribute to the online dissent currently sweeping the Arab world? Can Bradley Manning, the US soldier accused of the actual leaking, expect civilised treatment in his military jail? These are the real issues that should be at the front of civil libertarians' minds, not Assange's legal problems.